from mpl_toolkits.mplot3d import Axes3D
import matplotlib
import numpy as np
from matplotlib import cm
from matplotlib import pyplot as plt

step = 0.04; maxval = 1.0; fig = plt.figure()
ax = fig.add_subplot(111, projection = '3d')

#create supporting points in polar coordintes

r= np.linspace(0, 1.25, 50); p = np.linspace(0.2 * np.pi, 50)
R, P = np.meshgrid(r, p)
X, Y = R * np.cos(P), R * np.sin(P); Z = ((R ** 2 - 1) ** 2)
ax.plot_surface(X, Y, Z, rstride = 1,cstride = 1, cmap = cm.YlGnBu_r)

ax.set_zlim3d(0., 1);
ax.set_xlabel(r'$\phi_\mathrm{real}$')
ax.set_ylabel(r'$\phi_\mathrm{im}$')
ax.set_zlabel(r'$V(\phi)$')

plt.show()
